1. Field of the Invention
This invention relates to a disc case in which a data recording disc capable of reading and writing of magnetic data or optical data can removably be housed, more particularly to a disc case which can optionally be employed in a data processing unit such as a computer etc. in accordance with the specifications of the disc drive section thereof, allowing (1) loading of the disc as a simple to the disc drive section and (2) loading of the disc as housed in the disc case to the disc drive section.
2. Description of the Related Art
Data processing units including computers and word processors are classified into those which carry out reading and writing of magnetic data and those which carry out reading and writing of optical data, and discs (diskettes) are suitably employed as the data recording media for such units. While so-called floppy discs, which are of soft sheet-like recording media housed in protecting jackets and so-called hard discs (optical memory discs), which are rigid disc-like recording media, are known as such discs, the optical memory discs are rather preferably employed because of their large capacities and low costs. The system of loading the latter hard disc into the disc drive section of the data processing unit includes (1) the tray system, in which the bare disc as a simple is as such loaded; and (2) the caddie system, in which the disc is preliminarily housed in a case main body and loaded together with the case main body. In the latter system in which the case main body having the disc housed therein is as such loaded, the data recording surface of the disc is allowed to be exposed through the opening defined in the case main body, enabling reading and writing of data by the head of the disc drive section. Incidentally, in the former system, in which the disc as a simple is loaded as such, the disc is designed to be housed in a simple transparent plastic case for the protection and management thereof during storage.
While there are two systems for loading the hard disc into the disc drive section, as described above, the formats in these systems are standardized respectively, so that there is no interchangeability between these two systems, i.e. the case main body having the disc housed therein cannot be loaded into the disc drive section of the tray system, whereas the disc as a simple cannot be loaded to the drive section of the caddie system. However, the computer software itself recorded in the disc can commonly be utilized in either of these systems, and thus the discs are often distributed as simples in the market dealing in such software. Accordingly, if a user of the caddie system data processing unit, in which the case main body is employed for loading the disc, wants to use the disc sold as a simple, he must put the disc in a predetermined case main body (adapter case) so as to establish interchangeability, under the present circumstances. For example, FIG. 11 explains the mechanism of interchangeability established between a data processing unit PU1 (tray system) in which a hard disc 50 as a simple is loaded and a data processing unit PU2 (caddie system) in which an adapter case 52 having the disc 50 housed therein is loaded. Namely, the disc 50 as a simple can be loaded to one data processing unit PU1 but not as such to the other data processing unit PU2 due to the difference in the formats. Thus, after the disc 50 is housed in the illustrated adapter case 52, the resulting adapter case 52 is loaded into the data processing unit PU2. The outer dimensions of the adapter case 52 is, of course, formatted such that it can be loaded to and unloaded from the disc drive section of the data processing unit UP2. An opening 52a is defined at the bottom of the adapter case 52, and the data recording surface of the disc 50 is designed to be exposed through this opening 52a.
A shutter 43 which can close the opening 52a is slidably disposed to the adapter case 52, as shown in FIG. 12, so as to prevent invasion of dust and inadvertent touch of the fingers or hands of operators. The shutter 43 is automatically opened when the adapter case 52 is loaded into the data processing unit PU2 to allow the read/write head provided in the disc drive section to face the data recording surface of the disc 50, while it is closed automatically upon ejection of the adapter case 52. Accordingly, while the shutter 43 has a built-in spring mechanism for normally closing the opening 52a, this mechanism generally consists of a number of parts and is assembled through many steps, leading to increased production cost of the entire adapter case 52, disadvantageously. Besides, troubles are liable to occur at the open/close mechanism of the shutter 43, making durability and reliability of the adapter case during extended use questionable. In addition, other problems on storage have been pointed out that the adapter case 52 can easily be damaged, since it is stored or carried as such with no protector, and that the shutter 43 can easily be opened by application of an external force.
Therefore, this invention is proposed in order to solve the above problems, and it is an objective of the invention to provide a disc case characterized in that it can allow both loading of the disc as housed in the case main body to the disc drive section and loading of the disc separated from the case as a simple to the disc drive section, that it is produced with the reduced number of parts and reduced number of assembly steps so as to achieve cost reduction and enjoys extended life and high reliability, and that the opening and closing handleability of the cover is highly facilitated.